Hi,
The situation is somewhat like my case. Have you checked the purity level of the protein in SDS PAGE. In that case you may try to introduce another purification step. regards Debajyoti On Fri, 05 Feb 2010 10:05:23 +0530 wrote >Hi, All, We are trying to crystallize a protein and found some initial hit in the following conditions, pH 4.8, 0.2 M AS or some other salts ( NaCl,LiCl, MgCl2 ), 32% PEG4000 or PEG3350 ). However the quality of the crystal is not so great,some of them look like needle cluster(very long in length), some of them look like multi-crystals or hollow inside. We tried to optimize the pH and PEG and tested one that diffracts at 2.9A. For the next, how to improve resolution?Any suggestions? Even mutate the protein to get a high resolution is ok, generally what kind of mutation would make proteins crystallize better? Thanks.